Journal of Polymer Science: Polymer Symposia最新文献_第10页

Underwater stress relaxation studies of nafion (perfluorosulfonate) ionomer membranes 全氟磺酸离子膜的水下应力松弛研究

Journal of Polymer Science: Polymer Symposia Pub Date : 1984-01-01 DOI: 10.1002/polc.5070710119

Thein Kyu, Adi Eisenberg

{"title":"Underwater stress relaxation studies of nafion (perfluorosulfonate) ionomer membranes","authors":"Thein Kyu, Adi Eisenberg","doi":"10.1002/polc.5070710119","DOIUrl":"10.1002/polc.5070710119","url":null,"abstract":"In an effort to elucidate the nature of ionic aggregation and its effect on the primary relaxation (α process) in the Nafion polymers (EW = 1200), underwater and undermethanol stress relaxation tests were conducted at various temperatures (20–70°C). Both semicrystalline and amorphous Nafion-Na relax faster in the presence of water than in the dry state. In marked contrast to the behavior observed for Nafions in the dry condition, the kind of countercations is insignificant in the underwater stress relaxation. The great similarity in the underwater stress relaxation curves for different cations is attributable to the reduction of ionic interaction between the bound anions and unbound cations, probably associated with the water shielding around the ionic species. This leads to the suggestion that the primary α relaxation may be relevant to the ionic groups rather than to the matrix Tg, representing a reversal of the original assignment of the mechanical α and β relaxations. Increased swelling in methanol shows a modulus being one order of magnitude lower than that in the underwater runs. However, little or no difference is seen in the rates of stress relaxation in the underwater and undermethanol stress relaxation experiments. It is postulated that methanol also interacts with the interracial regions or with the fluorocarbon matrix in the Nafions, not just with the ionic regions.","PeriodicalId":16867,"journal":{"name":"Journal of Polymer Science: Polymer Symposia","volume":"71 1","pages":"203-219"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/polc.5070710119","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83238626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 17

Conformational properties of perfluoroalkane chains. VI. Intrinsic viscosity and unperturbed dimensions of poly(decamethylene perfluorosebacate) 全氟烷烃链的构象性质。六、聚全氟癸二酸十亚甲基的特性粘度和无扰动尺寸

Journal of Polymer Science: Polymer Symposia Pub Date : 1984-01-01 DOI: 10.1002/polc.5070710110

Keizo Matsuo, W. H. Stockmayer, G. F. Needham

引用次数: 1

The transitions and melting behavior of thermally crystallized poly(ethylene terephthalate) and their correlations with ftir and density measurements 热结晶聚对苯二甲酸乙酯的转变和熔化行为及其与红外光谱和密度测量的关系

Journal of Polymer Science: Polymer Symposia Pub Date : 1984-01-01 DOI: 10.1002/polc.5070710113

Shaow-Burn Lin, Jack L. Koenig

引用次数: 6

The structure of crystals formed from dilute polymer solutions† 由稀聚合物溶液形成的晶体结构†

Journal of Polymer Science: Polymer Symposia Pub Date : 1984-01-01 DOI: 10.1002/polc.5070710115

R. C. Domszy, M. Glotin, L. Mandelkern

{"title":"The structure of crystals formed from dilute polymer solutions†","authors":"R. C. Domszy, M. Glotin, L. Mandelkern","doi":"10.1002/polc.5070710115","DOIUrl":"10.1002/polc.5070710115","url":null,"abstract":"The structures of crystallites formed from a dilute solution of linear polyethylene and of an ethylene-butene copolymer (hydrogenated polybutadiene) have been studied using several different methods. In addition to the conventional thermodynamic methods, small-angle x-ray scattering measurements and analysis of the low-frequency Raman longitudinal acoustic mode (LAM) were also carried out. The major objectives were to establish the level of crystallinity and to determine the thickness of the crystallite core. The results of these studies were also applied to the analysis of the literature data for isotactic polystyrene crystallites formed from dilute solution. For the linear chains and the isothermally crystallized copolymer the different methods gave essentially the same results. The thickness of the amorphous overlayer for the lamellas formed by the homopolymers was found to be about 25 Å, in agreement with previous conclusions. It represents about 20–30% of the lamellar thickness. For the isothermally crystallized copolymers, the overlayer thickness increases to as much as 60 Å and the level of crystallinity is reduced to about 50%. For the rapidly crystallized, small crystallite size copolymer there is a discrepancy in the sizes obtained by the different methods. Possible reasons for the differences are pointed out However, a rather large overlayer is still deduced. When examined in perspective, it becomes clear that the lamellar-like crystallites, typical of crystallization from dilute solution, contain a significant disordered overlayer. The relative extent of this overlayer depends on the chain structure.","PeriodicalId":16867,"journal":{"name":"Journal of Polymer Science: Polymer Symposia","volume":"71 1","pages":"151-166"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/polc.5070710115","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90336589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Stretching calorimetry and thermoelasticity of rubbers at different temperatures† 橡胶在不同温度下的拉伸量热法和热弹性

Journal of Polymer Science: Polymer Symposia Pub Date : 1984-01-01 DOI: 10.1002/polc.5070710120

H.-G. Kilian, G. W. H. Höhne, P. Trögele, H. Ambacher

引用次数: 5

Static and dynamic light-scattering studies of poly(vinyl acetate) in the glass transition region 聚醋酸乙烯酯在玻璃过渡区的静态和动态光散射研究

Journal of Polymer Science: Polymer Symposia Pub Date : 1984-01-01 DOI: 10.1002/polc.5070710121

J. Tribone, A. M. Jamieson, R. Simha

{"title":"Static and dynamic light-scattering studies of poly(vinyl acetate) in the glass transition region","authors":"J. Tribone, A. M. Jamieson, R. Simha","doi":"10.1002/polc.5070710121","DOIUrl":"10.1002/polc.5070710121","url":null,"abstract":"An optically clear sample of undiluted poly(vinyl acetate) (PVAc) has been prepared by UV-initiated bulk polymerization of monomer at 42°C. Measurements of light-scattering intensities in the temperature range Tg − 30°C > T > Tg + 50°C have been carried out. Photon correlation spectroscopy has been performed in the temperature range Tg + 5°C > T > Tg + 23°C. Intensity data for T < Tg are in agreement with the Einstein–Smoluchowski expression for density fluctuations, >δρ2; below Tg statistical thermodynamic formulation of >δρ2, evaluated using experimental equation-of-state information, is found to be in accord with the light-scattering results. Photon correlation functions are well described by a single Williams–Watts function. Mean relaxation times and associated activation energies are compared with results of other relaxational studies of PVAc. Discrepancies observed are interpreted to be due in part to variability of sample histories as well as to problems in analytical treatment of the pertinent relaxation spectra.","PeriodicalId":16867,"journal":{"name":"Journal of Polymer Science: Polymer Symposia","volume":"71 1","pages":"231-245"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/polc.5070710121","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84227846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Miscible blends of a vinylidene chloride/vinyl chloride copolymer with polymethacrylates 偏氯乙烯/氯乙烯共聚物与聚甲基丙烯酸酯的混相共混物

Journal of Polymer Science: Polymer Symposia Pub Date : 1984-01-01 DOI: 10.1002/polc.5070710114

E. M. Woo, J. W. Barlow, D. R. Paul

引用次数: 5

Published Polymer Symposia 已出版的聚合物专题讨论会

Journal of Polymer Science: Polymer Symposia Pub Date : 1984-01-01 DOI: 10.1002/polc.5070710124

引用次数: 0

Studies on adsorption of poly(vinyl butyral) and dispersibility of γ-fe2o3 in magnetic paints 聚乙烯基丁醛在磁性涂料中的吸附及γ-fe2o3分散性研究

Journal of Polymer Science: Polymer Symposia Pub Date : 1984-01-01 DOI: 10.1002/polc.5070710112

Katsuhiko Nakamae, Kenji Sumiya, Toshiaki Taii, Tsunetaka Matsumoto

{"title":"Studies on adsorption of poly(vinyl butyral) and dispersibility of γ-fe2o3 in magnetic paints","authors":"Katsuhiko Nakamae, Kenji Sumiya, Toshiaki Taii, Tsunetaka Matsumoto","doi":"10.1002/polc.5070710112","DOIUrl":"10.1002/polc.5070710112","url":null,"abstract":"The adsorption of poly(vinyl butyral) (PVB) at the γ-Fe2O3–benzene interface and the air–water interface was investigated by means of the adsorbance on γ-Fe2O3 and surface pressure (π)–area (A) curves. The adsorption isotherms of PVB on γ-Fe2O3 from the various solvents are of the Langmuir type and can be explained by competitive adsorption between PVB and the solvents. From the π–A curves of monolayers and the adsorbance on γ-Fe2O3, it was confirmed that the adsorbed PVB on γ-Fe2O3 is in a train-loop conformation with the hydroxyl groups and the butyral segments directed toward the solution phase. The packing density of γ-Fe2O3, particles in the magnetic coatings preferentially depends on the conformation of polymers on the particle surface. The PVB–solvent system which gives the most compact train-loop conformation gives the highest dispersion and packing of γ-Fe2O3 in the magnetic coatings.","PeriodicalId":16867,"journal":{"name":"Journal of Polymer Science: Polymer Symposia","volume":"71 1","pages":"109-119"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/polc.5070710112","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83188566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The radiation resistance of nylon-6† 尼龙-6†的耐辐射性能

Journal of Polymer Science: Polymer Symposia Pub Date : 1984-01-01 DOI: 10.1002/polc.5070710105

H. Wilski

引用次数: 4